[Qemu-devel] [RFC][PATCH 15/16 v8] support detached dump

[Wen Congyang <wency@cn.fujitsu.com>]

Let the user to choose whether to block other monitor command while dumping.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 dump.c           |    2 +-
 hmp-commands.hx  |    9 +++++----
 hmp.c            |   49 +++++++++++++++++++++++++++++++++++++++++++++++--
 qapi-schema.json |    4 +++-
 qmp-commands.hx  |    6 ++++--
 5 files changed, 60 insertions(+), 10 deletions(-)

diff --git a/dump.c b/dump.c
index 4c8038d..40eefb9 100644
--- a/dump.c
+++ b/dump.c
@@ -800,7 +800,7 @@ static DumpState *dump_init_fd(int fd, bool paging, Error **errp)
     return s;
 }
 
-void qmp_dump(bool paging, const char *file, Error **errp)
+void qmp_dump(bool detach, bool paging, const char *file, Error **errp)
 {
     const char *p;
     int fd = -1;
diff --git a/hmp-commands.hx b/hmp-commands.hx
index b936bb7..fd6f9f1 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -883,21 +883,22 @@ ETEXI
 #if defined(CONFIG_HAVE_CORE_DUMP)
     {
         .name       = "dump",
-        .args_type  = "paging:-p,file:s",
-        .params     = "[-p] file",
-        .help       = "dump to file",
+        .args_type  = "detach:-d,paging:-p,file:s",
+        .params     = "[-d] [-p] file",
+        .help       = "dump to file (using -d to not wait for completion)",
         .user_print = monitor_user_noop,
         .mhandler.cmd = hmp_dump,
     },
 
 
 STEXI
-@item dump [-p] @var{file}
+@item dump [-d] [-p] @var{file}
 @findex dump
 Dump to @var{file}. The file can be processed with crash or gdb.
     file: destination file(started with "file:") or destination file descriptor
           (started with "fd:")
   paging: do paging to get guest's memory mapping
+      -d: donot wait for completion.
 ETEXI
 #endif
 
diff --git a/hmp.c b/hmp.c
index 81dd23d..8652b20 100644
--- a/hmp.c
+++ b/hmp.c
@@ -857,14 +857,59 @@ void hmp_block_job_cancel(Monitor *mon, const QDict *qdict)
     hmp_handle_error(mon, &error);
 }
 
+typedef struct DumpingStatus
+{
+    QEMUTimer *timer;
+    Monitor *mon;
+} DumpingStatus;
+
+static void hmp_dumping_status_cb(void *opaque)
+{
+    DumpingStatus *status = opaque;
+    DumpInfo *info;
+
+    info = qmp_query_dump(NULL);
+    if (!info->has_status || strcmp(info->status, "active") == 0) {
+        qemu_mod_timer(status->timer, qemu_get_clock_ms(rt_clock) + 1000);
+    } else {
+        monitor_resume(status->mon);
+        qemu_del_timer(status->timer);
+        g_free(status);
+    }
+
+    qapi_free_DumpInfo(info);
+}
+
 void hmp_dump(Monitor *mon, const QDict *qdict)
 {
     Error *errp = NULL;
     int paging = qdict_get_try_bool(qdict, "paging", 0);
+    int detach = qdict_get_try_bool(qdict, "detach", 0);
     const char *file = qdict_get_str(qdict, "file");
 
-    qmp_dump(!!paging, file, &errp);
-    hmp_handle_error(mon, &errp);
+    qmp_dump(!!detach, !!paging, file, &errp);
+    if (errp) {
+        hmp_handle_error(mon, &errp);
+        return;
+    }
+
+    if (!detach) {
+        DumpingStatus *status;
+        int ret;
+
+        ret = monitor_suspend(mon);
+        if (ret < 0) {
+            monitor_printf(mon, "terminal does not allow synchronous "
+                           "migration, continuing detached\n");
+            return;
+        }
+
+        status = g_malloc0(sizeof(*status));
+        status->mon = mon;
+        status->timer = qemu_new_timer_ms(rt_clock, hmp_dumping_status_cb,
+                                          status);
+        qemu_mod_timer(status->timer, qemu_get_clock_ms(rt_clock));
+    }
 }
 
 void hmp_dump_cancel(Monitor *mon, const QDict *qdict)
diff --git a/qapi-schema.json b/qapi-schema.json
index 41428ed..bd258cb 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1637,6 +1637,7 @@
 #
 # Dump guest's memory to vmcore.
 #
+# @detach: detached dumping.
 # @paging: if true, do paging to get guest's memory mapping
 # @file: the filename or file descriptor of the vmcore.
 #
@@ -1644,7 +1645,8 @@
 #
 # Since: 1.1
 ##
-{ 'command': 'dump', 'data': { 'paging': 'bool', 'file': 'str' } }
+{ 'command': 'dump',
+  'data': { 'detach': 'bool', 'paging': 'bool', 'file': 'str' } }
 
 ##
 # @dump_cancel
diff --git a/qmp-commands.hx b/qmp-commands.hx
index c532561..e2accb2 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -589,8 +589,8 @@ EQMP
 #if defined(CONFIG_HAVE_CORE_DUMP)
     {
         .name       = "dump",
-        .args_type  = "paging:-p,file:s",
-        .params     = "[-p] file",
+        .args_type  = "detach:-d,paging:-p,file:s",
+        .params     = "[-d] [-p] file",
         .help       = "dump to file",
         .user_print = monitor_user_noop,
         .mhandler.cmd_new = qmp_marshal_input_dump,
@@ -618,6 +618,8 @@ Notes:
 (1) All boolean arguments default to false
 (2) The 'info dump' command should be used to check dumping's progress
     and final result (this information is provided by the 'status' member)
+(3) The user Monitor's "detach" argument is invalid in QMP and should not
+    be used
 
 EQMP
 #endif
-- 
1.7.1